1. Field of the Invention
The present invention relates to sliding caliper disc brakes of the type in which a caliper member, which is slidably mounted on a torque member and straddles a minor portion of the periphery of a rotatable disc, includes an actuator for directly urging a friction pad into engagement with one side of the disc whereupon the caliper member slides relative to the torque member and applies by reaction an opposite pad to the other side of the disc. More specifically, the present invention relates to a sliding pin arrangement between the caliper and the torque member.
2. Description of the Prior Art
When a sliding connection between a caliper member and a torque member is provided by a pair of supporting pins fixed to the caliper member and slidable in openings in the torque member, increased resistance to sliding arising from corrosion and dirt may be avoided by sealing the sliding surfaces of the supporting pins and their openings. However, it is important to ensure that the pins and openings are accurately aligned and parallel. Any appreciable deviation, which will typically be on the order of inaccuracies expected in mass-production manufacture, will affect the ease with which the caliper member will slide on the torque member resulting in uneven braking when, for example, two nominally indentical brakes with different sliding characteristics are mounted at the front wheels of a vehicle. An additional problem arises during heavy braking from deflection of the torque member resulting in objectionable misalignment between the pins and openings.
The U.S. Pat. No. 4,094,389 to Brix et al granted June 13, 1978 shows a typical arrangement for slidably supporting a caliper for axial movement relative to a support member. A pair of pins 20 are secured to the caliper and are slidably disposed in parallel bores formed in the fixed support.
The U.S. Pat. No. 4,074,795 to Kondo granted Feb. 21, 1978 slidably supports the caliper on the support member by a pair of parallel pins secured to the arms of the support member and extending into a pair of oversized bores on the caliper. Deformable resilient spacers are located within the bores in sliding relation to the pins to accommodate minor misalignments.
The U.S. Pat. No. 4,061,209 to Gee et al granted Dec. 6, 1977 discloses a disc brake wherein the caliper is mounted for axial sliding movement relative to the support by means of a pair of parallel pins rigidly secured to opposite side of the caliper and disposed in oversized bores in the support member. A spring member is provided to normally bias the pins into an eccentric position in direct sliding contact with the wall of the respective bore to prevent rattling while allowing deformation of the support during braking without unduly binding the pins within the bores.